新水溶性显色剂2,6-二溴-4-硝基-4′-(β-硫酸酯乙基)磺酰基苯基重氮氨基偶氮苯的合成及其与镉的显色反应

Synthesis of a new water miscible reagent 2,6-dibromo-4-nitrophenyl-4'-(β-ethyl sulfate) sulfonylbenzenediazoaminoazobenzene and its colour reaction with cadmium

合成了新型水溶性显色剂标题化合物（DBNSESDAA）。在pH8．0的硼砂-盐酸缓冲介质中，Triton X-100存在下，该试剂与镉（Ⅱ）生成络合比为3：1的红色配合物。试剂有很好的灵敏度、选择性和水溶性。用双波长法测得表观摩尔吸光系数ε为2．1×10^5L·mol^-1·cm^-1，镉量在0～20μg／25mL范围内遵守比尔定律。用该试剂测定了电池厂废水和环境水中的痕量镉，结果满意。

A new water soluble reagent 2, 6-dibromo-4-nitrophenyl-4＇-（β-ethyl sulfate） sulfonylbenzenediazoaminoazobenzene （DBNSESDAA） was synthesized. In the pre-sence of Triton X- 100, Cd （Ⅱ） reacted with DBNSESDAA to form a red complex with a molar ratio of 1 ： 3 in a medium of borax-HCl buffer of pH 8.0. Its apparent molar absorptivity was 2.1×10^5 L·mol^-1·cm^-1 as determined by the dual-wavelength spectrophotometry. The Beer＇s law was obeyed in the concentration range of 0～20 μg/25 mL for Cd（Ⅱ）. The reagent had good sensitivity, selectivity and water solubility. It had been used to determine Cd （Ⅱ） concentration in wastewater and environmental water of battery factory successfully.